Power and bandwidth are fundamental resources in communication, playing a key role in determining the effective capacity of a wireless channel [1]}, [2]}.
In modern wireless communication systems, the scope of resources has been broadened to include beams in a multiple-input-multiple-output (MIMO) system, time slots in a time-division multiple access system (TDMA), frequency sub-bands in a frequency-division multiple access (FDMA) system, spreading codes in a code-division multiple access (CDMA) system, among several others [3]}.
Optimal allocation of these resources under randomly varying channel characteristics and user demands is essential for the smooth operation of wireless systems.
In particular, power allocation in a wireless ad hoc network is crucial to mitigate multi-user interference, one of the main performance-limiting factors.
In addition, transmission power of a mobile user is in itself a scarce resource.
Indeed, careful and efficient power allocation is vital to prolong the battery life of mobile users [4]}.
